Discovered the first of the best known caves of Castellana (1931-1935), the Grotta del Trullo was the first to be considered a site of tourist interest in the whole of Puglia.
The story tells that it was May 29, 1931 when during some works for the construction and expansion of the sewer system of the entire city area, the workers involved in the excavation presented a chasm that gives access to a "vast cave of stalactites and stalagmites". The cave manifests all its splendor with limestone protuberances with shades of colors ranging from amber to ivory.
About a month later and precisely on June 28, 1931 at the request of the then Podestà of Putignano Cav. Ernesto Losavio, an official request was made to the Ministry of Education to be able to place the "natural karst cave" under protection according to law no. 778 of 11 June 1922.
In anticipation of a flow of visitors that would increase with the spread of the news of the discovery of this site in the south east of Bari, in April 1934 it was decided to raise a "modest building" to give guests "a minimum of rest or refreshment. ". The building can only respect the structural characteristics of the common houses in the Itria Valley, namely the trullo. The construction has three cones and closes the entrance to the cave like a hat. The site takes its name from this construction.
The formal inauguration was on 21 June 1935 personally officiated by the Prince of Italy Umberto II of Savoy, at the invitation of the Marquis Guglielmo Romanazzi Carducci, Podestà of the town.